(1) Field of the Invention
The present invention relates to linalool metabolizing Pseudomonas strains including plasmid pSRQ60 which encodes for metabolism of linalool. In particular, the present invention relates to Pseudomonas putida strains containing plasmid pSRQ60 and to a method for metabolizing linalool using such strains. The present invention also relates to producing a useful metabolite, i.e. 6-methyl-5-hepten-2-one.
(2) Prior Art
The prior art has described various Pseudomonas strains which degrade aliphatic and aromatic compounds. In some instances the degradation is encoded by genes on a chromosome and in other instances by genes on a plasmid. Examples of such Pseudomonas strains are described by Chakrabarty et al. Proc Nat Acad Science USA 70 No. 4 1137-40 (1973); Bensen et al., J. of Bacteriology 126 794-798, (1976); Pemberton et al., Nature 268 732-733, (1977). Bensen et al., J. of Bacteriology 132 614-621, (1977) and Vandenbergh et al., Applied and Environmental Microbiology 42, 737-739, (1981).
The prior art has also decribed Pseudomonas citronellolis for degrading isoprenoids, particularly Seubert W. in J. Bacteriology 79 426-434 (1960) and Cantwell et al. in J. Bacteriology 135 324-333, (1978). Pseudomonas citronellolis ATCC 13674 was surveyed for its extrachromosomal deoxyribonucleic acid (DNA) content, following the procedure of Hansen and Olsen, Nature (London) 274: 715-717 (1978). P. citronellolis ATCC 13674 was observed to contain no resident plasmids. The metabolites of this strain do not include 6-methyl-5-hepten-2-one. Linalool has the structure: ##STR1## the numbered positions in the structure are not conventional but have been used in the literature.
Geraniol has the formula ##STR2## by conventional nomenclature it is 3,7-dimethyl-2-6 octadien-1-ol. The similarity of geraniol to linalool can be seen in relation to the position of the hydroxyl group. These compounds are characterized as isoprenoids and as an acyclic monoterpenes in view of their citrus fruit origins.
Madgastha et al, Canadian Journal of Microbiology 23:230-239 (1977) describe the metabolism of linalool by a Pseudomonas isolated from soil. This strain acted upon the 10 position of linalool to produce 10-hydroxy derivatives. There was no evidence of any oxidation of the 1 or 2 position of linalool.
Renganathan et al Applied and Env. Microbiol. 45:6-15 (1983) describes the metabolism of linalool and linalool derivatives by Pseudomonas incognita. In this instance, the C-8 position is oxidized.
The pathways of degradation of linalool described by these later references does not involve the C.sub.1 to C.sub.3 carbon atoms. The degradative pathway for geraniol involves the formation of an enzyme intermediate. As can be seen from Cantwell, et al, the enzyme intermediate is formed by the elimination of acetic acid. This intermediate containing 9 carbon atoms is further oxidized and degraded. Thus the pathway involves the C.sub.1 to C.sub.x sequentially carbon atoms.